In a time-of-flight (TOF) depth camera, light pulses are projected from a light source to an object in an image environment that is focused onto an image sensor. It can be difficult to fill the image environment with illumination light, as the image environment may have a sizeable volume and may have a cross-sectional shape (e.g. rectangular) that does not match a shape of a light beam from the light source (e.g. round). Further, the imaging optics may have a large depth of field in which a consistent projected light intensity is desired.
Some previous approaches to achieving a desired illumination light shape employ random arrangements of microlenses. However, because such microlenses are randomly sized and distributed, the ability to control the distribution of light within the image environment, including the light's cross-sectional profile and the dimensions of the envelope that it illuminates within the room, may be compromised.